U.S. Constitution - Article 4 Section 2

Article 4 - The States
Section 2 - State Citizens, Extradition

The Citizens of each State shall be entitled to all Privileges and
Immunities of Citizens in the several States.

A Person charged in any State with Treason, Felony, or other Crime, who shall
flee from Justice, and be found in another State, shall on demand of the
executive Authority of the State from which he fled, be delivered up, to be
removed to the State having Jurisdiction of
the Crime.

(No Person held to Service or Labour in one State, under the Laws thereof, escaping
into another, shall, in Consequence of any Law or Regulation therein, be
discharged from such Service or Labour, But shall
be delivered up on Claim of the Party to whom such Service or Labour may be due.)(This clause in
parentheses is superseded by the 13th
Amendment.)